If it were me, I'd go for #2 (condition of the units being equal). I'm also partial to lots of light, so that would factor into my decision. My last apartment before I bought my latest house in August was light and airy and had a w/d, but it was right near the dumpsters and the trash chute for the building. It didn't smell but it was loud.

A w/d is mandatory for me. I just hooked up my washer and dryer in my little house (the plumbing had to be brought up to code) after a few months of taking my clothes to my BF house all the time. I'd sell your full size ones and go for the stackable unit. Besides stackables are really fine--they are not inferior in my experience.

For me, being near a trail is a big plus, particularly if that trail goes somewhere that I want to go!